The present invention relates to an actuating mechanism for setting a manipulatable member in at least two degrees of freedom of movement. The actuating mechanism includes at least one drive motor, whose output shaft is gear-connected to a manipulatable member driven reduction gear, and includes two potentiometers, which measure the actual position of the manipulatable member and are mounted on a printed circuit board and include electrical resistance paths, electrical contacting wipers and a drive housing.
German Patent PS 197 24 725 discloses a device for electrically setting the inside and outside mirror of a motor vehicle. The device provides as the adjusting elements two electric minimotors, which are held in a drive housing and which are driven electrically by a printed circuit board provided with at least one conducting and one resistance path. In the case of this prior art drive, the wipers are mounted separately from the printed circuit board on other components. Thus, the function of the potentiometer cannot be tested until it is mounted.
The object of the invention is to provide an actuating mechanism for setting a manipulatable member in at least two degrees of freedom of movement. The actuating mechanism is constructed at least in part modularly, so that one function of the potentiometer can be tested before installation into the actuating mechanism, which includes as few components as possible, can be mounted as easily as possible and whose potentiometer can be mounted easily without play with reference to the manipulatable member and/or the reduction gear.
The invention solves this problem in that the printed circuit board includes a deflector, which is at least partially embedded in plastic material and electrically connects the ends of the individual resistance paths to the contact points so that the resistance paths are carried between their ends by the plastic material. The contact point wipers are fastened on wiper carriers, which are designed in the form of gearwheels, frictional wheels or crank disks, are pivot-mounted on the printed circuit board and are gear-connected to the reduction gear and/or the manipulatable member. The printed circuit board is bent at an angle at at least one point, whereby the resistance paths of both potentiometers are configured in different planes, and the circuit board with the potentiometers and the contact points form one component, whereby the two potentiometers of the component are not mounted rigidly.
The design of the circuit board as a deflector, embedded in plastic material, makes it possible to make the circuit board any arbitrary shape so that it can also be adapted to complicated installation conditions. The contact points make it easier to make contacts and to install the circuit board. Mounting the carriers for the electrical contact wipers on the circuit board enables manufacture of a component with complete potentiometers. Thus, the component can be produced separately and its function can be tested before installation into the actuating mechanism.
The design of the carriers for the electrical contact wipers as gearwheels, frictional wheels or crank disks facilitates the mechanical coupling of the potentiometers to the reduction gear and/or the manipulatable member. By bending down the circuit board at an angle, the potentiometers can be installed in different planes. Nevertheless, installation of the potentiometers in one plane prior to bending down is possible, a state that is better for production. Since the two potentiometers are not rigidly arranged relative to each other, it is possible to balance the tolerances and thus the play between the potentiometers and the reduction gear and/or the manipulatable member.
It is advantageous for the plastic material of the printed circuit board to be made as one piece with the fastening means for fastening the circuit board in the drive housing. Thus, additional parts for attachment are superfluous. The assembly is easier if the circuit board is designed so as to snap into the drive housing.
To obtain freedom from play between the carriers for the electrical contact wipers and the reduction gear and/or the manipulatable member, it is advantageous for the circuit board to be designed in such a manner that it can be tilted to a limited degree in the drive housing. Thus, it is easier to produce and maintain the alignment between drive housing, circuit board and reduction gear, when the circuit board is in the drive housing. Preferably there are guides, which extend at a right angle to the axis of the gear elements, which are coupled directly to the wiper carriers of the potentiometers.
An especially advantageous design of the invention consists of the deflector being designed as one piece with the springy areas, because in this manner freedom from play can be produced between the wiper carrier and a gear element. Preferably the circuit board is divided into three areas; into a contact area and two potentiometer areas, whereby the contact area is connected, on the one hand, via several conducting paths of the deflector to the one potentiometer and, on the other hand, to the other potentiometer area; and the conducting paths form the springy areas. This design is especially compact, because the design of the conducting paths makes it possible to set the spring force. Preferably the circuit board is bent in such a manner that the installation of the drive housing results in a prestress.
It is logical to precisely run the potentiometer areas in the guides, since they lie in the vicinity of the plane of the wiper carriers. Furthermore, each potentiometer area is provided with one connecting part, into which a complementary connecting part of the housing can be snapped. In so doing, it is important, especially when it involves a ball joint and not a cylindrical joint, that at least one possible swivel axis runs parallel to the axis of rotation of the corresponding drive element in order to make it possible for the respective potentiometer area to swing to a limited degree with respect to the gear element.
To pivot-connect the wiper carriers to the circuit board, the wiper carriers are mounted on the circuit board using a rotating snap connection. To ensure that the wiper carrier is in an optimal position relative to the gear element with which it meshes and to ensure that the position is adequately stable, the circuit board has additional guides, which guarantee tilt-proof positioning of the wiper carrier.
The contact area makes it possible for the circuit board to make easy contact. The contact area can be connected as a component of the circuit board to the at least one drive motor by simply inserting into the connector of the drive housing.
In specific embodiments it can be advantageous to electrically and mechanically connect the drive motor(s) to the circuit board. Thus, it is not necessary to provide additional measures for the contacting of the motors in the drive housing.
It is possible to guarantee contact if the contact points of the contact area comprise two or four opposing tongue-shaped contacts, in which the corresponding counter contacts comprise flat contact tags or contact pins, whose thickness is greater than a free space between the tongue-shaped contacts. When inserting, these tongue-shaped contacts become snagged in the contact tags or pins and maintain the connection. It is possible to have an even smaller number of components, if the drive housing is made as one piece with the circuit board.
The uncovered problem is solved by the following inventive process:
punch deflector with conducting paths, whereby a holding frame and/or holding webs are left as auxiliary means to hold the conducting paths;
embed parts of the deflector in plastic material;
print circuit board in resistance paths;
harden the resistance paths;
remove the holding frame and/or the holding webs; and
bend the circuit board.
This process makes it possible to produce the potentiometers in the traditional manner, because the main components of the circuit board are arranged, first of all, in one plane. Even the punching of the deflector, the embedding and the removal of the holding frame can be accomplished in a simple manner as long as the circuit board has not yet been bent. Bending the board results in a special shape that is mandated by the respective application. Of course, applications without having to bend the circuit board are also conceivable.